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Double-Door Garage Conversion

Basement, Construction How-To, Doors, Garages August 19, 2015 Sonia



Replace an overhead door with pre-hung double panels.

By Matt Weber

 

 

 

 

 

 

 

To increase the finished living space in a split-level home, we removed a garage door and replaced it with a double door to remodel the interior into a family room. This insulated fiberglass door was smaller than the garage door opening, which required us to frame the new opening. Replacing a door usually presents the challenge of installing the door snugly and securely into the existing rough opening. In this case, however, we built the rough opening to fit the door. Here’s how we tackled the project.

The goal of this project: Replace the overhead garage door with a double door so the interior can be remodeled as a family room.

The goal of this project: Replace the overhead garage door with a double door so the interior can be remodeled as a family room.

Non-load-bearing Framing

It’s important to note that we framed this door as a non-load-bearing wall. Most exterior doors require a load-bearing header installed directly above the jamb. Headers are structural framing members made from doubled 2x lumber that bridge the rough opening of a door or window to distribute the overhead weight that would otherwise fall on the missing studs. The size of the header depends on the span of the opening and whether or not it is a load-bearing wall.

First step is to remove the door-opener mechanism, including the chain, tracks and motor.

First step is to remove the door-opener mechanism, including the chain, tracks and motor.

In this case, we removed the existing garage door, which had already been constructed with a substantial header, and left the structural framing in place to carry the load. We then constructed a secondary wall just inside the framed opening to house the new double door. Because the existing header satisfied the load-bearing requirements, the secondary wall serves only to define the rough opening, enclose the sides of the door, and provide a nailing surface for wallboard and sheathing. Since the new, secondary header was not a load-bearing component, we built it with doubled 2×4 lumber.

To disassemble a garage door, unscrew the individual panels one at a time, working from the top downward.

To disassemble a garage door, unscrew the individual panels one at a time, working from the top downward.

Determining Placement

First step was to take a few measurements to center the double door in the opening. We calculated the proximity of the new wall to the existing frame by accounting for the thickness of the sheathing that would be installed between them. We then snapped a chalk line on the floor to guide placement of the door jamb and new wall.

For this project we were able to position the new door and build the rough opening around it.

For this project we were able to position the new door and build the rough opening around it.

At least two people are required to move a double door. Placing the pre-hung door and jamb into the opening, however, enabled us to easily make accurate measurements and layout marks to build the surrounding frame.

This diagram shows a standard door frame. Because of the garage door's existing header, the new, secondary door frame was a nonload-bearing wall so we built the header from doubled 2x4. For a load-bearing wall the header would need to be larger and supported by trimmer studs.

This diagram shows a standard door frame. Because of the garage door’s existing header, the new, secondary door frame was a nonload-bearing wall so we built the header from doubled 2×4. For a load-bearing wall the header would need to be larger and supported by trimmer studs.

Sometimes when installing a replacement door the jamb is a little too small for the opening, requiring shims or trim-boards for adjustment. When framing around a door, though, you can construct the frame with as tight a surround as you want—just leave enough fudge room to allow maneuvering the door into the rough opening. Building around the door also enables you to eliminate the out-of-square framing errors associated with the house settling (or poor carpentry). Always make sure to build the rough opening plumb, square and true for doors and windows, ensuring no studs are bowed.

Building the Frame

We constructed the wall with a typical sill plate, bottom plate, and studs spaced 16 inches on center. We anchored the sill and installed a top plate with two studs on each side of the door. We then removed the door and set it aside while we continued construction of the wall.

Anchor the wall's sill plate to the slab with concrete screws.

Anchor the wall’s sill plate to the slab with concrete screws.

Installing sheets of rigid foam insulation with a moisture barrier helps to weather-proof the building envelope of the new frame. We nailed the foam sheets over the face of the frame and cut it to fit. Apply flashing tape to seal the edges of the rigid foam to the surrounding frame. Use a sill plan to ensure moisture protection at the bottom of the door jamb.

Cut the top plate to span the opening and allow studs spaced on both sides of the door. The top plate is fastened to the ceiling joists.

Cut the top plate to span the opening and allow studs spaced on both sides of the door. The top plate is fastened to the ceiling joists.

Installation

We applied beads of sealant along the bottom of the opening, including the seams at the lower corners, and inserted the pre-hung door frame from the outside of the house. Don’t slide the door in place, however, which messes up the sealant beads. It’s best to tilt it into position and then make adjustments.

Install studs cut to fit between the sill and top plate, framing the sides of the rough opening.

Install studs cut to fit between the sill and top plate, framing the sides of the rough opening.

Refer to the manufacturer’s instructions for specific steps to install your door, because methods may vary among models. In general you should center the jamb in the door frame, then drive one 10d finish nail or 3-inch screw through the mid-point of each hinge jamb into the framing studs. The nails or screws are used to hold the door in place while you plumb and square the jamb, using shims if necessary. Place the shims at the hinge locations between the jamb and the studs. Use shims in other locations as needed to square the opening. Check for square by measuring the diagonals of the jamb in an X pattern (corner to corner) to confirm they match.

Make sure the studs are installed square, plumb and true and that the boards are straight and not bowed.

Make sure the studs are installed square, plumb and true and that the boards are straight and not bowed.

On double doors, it’s important to make sure the door panels are even across the top and bottom and that the reveal between them is even.

Toe-nail the studs in place at the top and bottom.

Toe-nail the studs in place at the top and bottom.

Pre-hung doors often include long screws that insert into the open holes of the door’s hinge(s) once the door is in final position. When driving the screws, make sure not to bow the sides of the door jamb.

We installed the nonstructural 4x4 header.

We installed the nonstructural 4×4 header.

After checking to make sure the door opens and closes properly, continue fastening the jamb to the frame with 10d finish nails or predrilled 3-inch screws.

Rigid foam sheets helps to insulate the wall.

Rigid foam sheets helps to insulate the wall.

Finishing Touches

As with any new door installation, the edges and air gaps should be insulated and sealed with spray foam and caulk.

The foam sheets should be nailed to the wall studs.

The foam sheets should be nailed to the wall studs.

Use a utility knife to cut the foam sheet to fit the wall.

Use a utility knife to cut the foam sheet to fit the wall.

Apply adhesive sealant to the bottom of the rough opening.

Apply adhesive sealant to the bottom of the rough opening.

Refer to the manufacturer's instructions for specific steps to install your door. They often come with ong hinge screws that are driven through the hinge locations of the jamb, through shims and into the stud framing. Make sure not to bow the sides of the door frame.

Refer to the manufacturer’s instructions for specific steps to install your door. They often come with ong hinge screws that are driven through the hinge locations of the jamb, through shims and into the stud framing. Make sure not to bow the sides of the door frame.

Confirm the door functions properly before installing additional fasteners to hold the jamb in place.

Confirm the door functions properly before installing additional fasteners to hold the jamb in place.

Pro Tip: Insert a foam backer rod around the brick-mold of the door as deep as it will go to provide at least 3/8-inch clearance from the surrounding siding. Caulk over the backer rod with a bead of quality exterior-grade sealant, and tool the caulk bead smooth. This method creates a flexible sealant line around the door that is capable of expanding and contracting.

Short cripple studs fit between the header and top plate. Doubled wall studs frame each side of the door jamb. The wall is then insulated with fiberglass batts.

Short cripple studs fit between the header and top plate. Doubled wall studs frame each side of the door jamb. The wall is then insulated with fiberglass batts.

Baseboard trim hides the transition between the new wall and the garage opening.

Baseboard trim hides the transition between the new wall and the garage opening.

Make sure each course of cement siding is level and install according to the manufacturer's fastening instructions.

Make sure each course of cement siding is level and install according to the manufacturer’s fastening instructions.

For this project, we finished the exterior wall with cement siding, trim boards and a new coat of matching paint. Two decorative outdoor wall fixtures wired into the new wall gave the new double doors a finishing touch that greatly added to the curb appeal of the home.

The project was completed with two wall-mounted light fixtures and a matching coat of paint.

The project was completed with two wall-mounted light fixtures and a matching coat of paint.